Academic Thesis

Sound means a variation of air pressure (air compression and decompression) that passes through air and can be detected by human ears when it reaches to human hearing systems. Noise, on the other hand, is a kind of sound that is remarkably loud. It is characterized by its unpleasant and annoying nature that can even lead to some physical illness. Aside from hearing loss, noise can also induce severe cardiovascular symptoms of increased heart rate and can bring about psychological effects that manifest as anxiety, lack of concentration, and profound nervousness. Workers of several professions such as mining, construction, transportation, manufacturing, agriculture and so one face more or less noise hazards every day. According to World Health Organization (WHO) approximately 5% of the world population suffers from noise pollution to some extent. However, the objective of this study was to evaluate the indoor noise level of a village house in Dkshindihi, which is located in Phultola upzilla of Khulna district in Bangladesh. The latitude and longitude of the location was 22.98483 and 89.46137, respectively. The raw data was captured by using ‘Sound Level Meter’ app of smart phone. The study was conducted for a month (from 05 July 2020 to 04 August 2020). Every day data was taken from 7:00 AM to 10:00 PM where 7:00 AM to 5:00 PM was considered daytime while 6:00 PM to 10:00 PM was considered as night time. For the sake of analysis, the study period was divided into three segments where in each segment 10 days were considered. In the first ten-day-period, the average sound level was measured to be 66.12 dB and 68.05 dB in day time and at night, respectively. A similar scenario was observed for the second ten-day-period. It was found that the average sound level in day time was 66.07 dB and at night time it was 61.01 dB. In the last ten-day segment the values were 69.80 dB and 64.72 dB for day time and night time, respectively. However, the mean value of sound level of all 30-day-period was also calculated. It was found that the mean sound intensity at day time was 67.33 dB while at night it was 64.72 dB. However, the standard value of sound level in Bangladesh (for quiet zone or silent zone) is reported to be 50 dB and 40 dB in daytime and nighttime, respectively. It is obvious that the indoor sound level of the studied location was much higher than that of the standard value both in day time and at night. Indoor noise problem is perhaps caused by several issues, which include but not limited to inadequate residential planning, lack of maintenance of residential houses, improper placement or setting of various household electrical as well as mechanical equipment (television, radio, oven, washing machine, sewing machine, motor for water pumping etc.), entering of outside noise, and tendency of inhabitants to speak loudly at home. The results obtained from this study clearly reveal the alarming condition of noise pollution in the studied area. The assessment also suggests that an immediate measure should be taken to mitigate and manage noise pollution problems.